Silicon Compounds, Silicones

Abstract

This article begins with an introduction on common shorthand nomenclature and a history of silicones. The chemistry discussion includes a description of the direct process for formation of monomers, including the methylchlorosilane process. The silicone polymerizations described are condensations, anionic and cationic ring‐opening polymerizations, emulsions, radiation‐induced polymerizations, and plasma reactions. Discussion of silicone network formation includes those formed via peroxides, hydrosilylation, condensation, high energy, and uv radiation. Methods of characterizing silicone networks are discussed, as well as model, monodisperse, and filled networks. A section on silicone properties and uses includes discussion of fluids, heat‐cured rubber, liquid‐injection‐molding rubber, hardcoats, release coatings, and resins. A discussion of resins includes sections devoted to characterization, structure, synthesis, and applications. Room‐temperature‐vulcanized (RTV) silicones are reviewed with sections on moisture‐curable silicones, basic RTV chemistry, RTV compositions, properties, and applications. Analysis and testing of silicones are described, along with chemical analysis, instrumental methods, and determination of physical properties. Important new developments are given on health and environmental aspects of silicones. Economic aspects of the silicones industry are summarized.

Mechanism of Chlorine-Mediated Electrochemical Ethylene Oxidation in Saline Water

“…Ethylene oxide has also been produced industrially via the chlorohydrin process. Ethylene and chlorine react with water to generate 2-chloroethanol, and subsequent treatment with a base such as calcium hydroxide produces ethylene oxide. , However, the cost of generating Cl 2 gas and the generation of a stoichiometric amount of chloride salts as waste products has led to the process being replaced by the direct oxidation process.…”

Direct Human Contact with Siloxanes (Silicones) – Safety or Risk Part 1. Characteristics of Siloxanes (Silicones)

“…At the end of the reaction, the reactor contains the mixture of linear polysiloxane and about 15% of cyclic oligomers ( Noll, 1968 ; Voronkov et al, 1978 ; Rubinsztajn et al, 1989 ; Colas and Curtis, 2004 ). Polymerization of cyclic siloxanes was elaborated in the US in the fifties by General Electric Co. and Dow Corning ( Noll, 1968 ; Rich et al, 1997 ). The polycondensation of linear hydroxyl-terminated oligosiloxanes using a catalyst of linear phosphonitrilic chloride produces linear high molecular polymers.…”

Preparation and characterization of polysiloxane networks containing metallic platinum particles

“…It can be applied in the synthesis of monomers and in the formation of much bigger, extended products, such as three-dimensional networks via the cross-linking reaction of multifunctional silicon hydride polymers with multifunctional silicon vinyl polymers. [19][20][21][22] One of the most commonly used catalysts for the hydrosilylation reaction is the Karstedt's catalyst. 23,24 As mentioned above, selected hydrosiloxanes, i. molar ratios were used as crosslinking agents for the preparation of polysiloxane networks.…”